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A 30.01.2012 ISSUED FOR INFORMATION O.Y O.Y E.D
Rev.No. Date Description
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ORIGINATOR Published by
EDOPEC ENERJİ PETROL MÜHENDİSLİK SANAYİİ VE TİCARET LİMİTED ŞİRKETİ
Contractor
Document Title
Corrosion Management and Cathodic ProtectionOffice :
Palmiye Mah. Adnan menderes Bulv. Oktay SitesiNo: 9/8 PK = 33100 Yenişehir /Mersin –TURKEYP:+90 324 3260595 F:+90 324 3260596Ankara Office :UĞUR MUMCU CAD(köroğlu cad) ERDİL APT 87/13 Gop-Çankaya -Ankara-TURKİYEP: +90 312 447 17 18 / 20F:+90 312 447 17 21İstanbul Office: Burhanıye Mahallesı Çamlıca Caddesi İhlamur villaları no 28 / 6^ŞRD3K Villa ̂ Beylerbeyi –Üsküdar İstanbul / TURKEYP : +90 216 4220414 PBXF: +90 216 4220415www.edopec.com. [email protected]
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Head Office : Palmiye Mah. Adnan menderes Bulv. Oktay Sitesi No: 9/8 PK = 33100 Yenişehir /Mersin –TURKEYP:+90 324 3260595 F:+90 324 3260596Ankara Office : UĞUR MUMCU CAD(Köroğlu cad) ERDİL APT 87/13 Gop-Çankaya -Ankara-TURKİYEP: +90 312 447 17 18 / 20 F:+90 312 447 17 21İstanbul Office: BURHANIYE MAHALLESI ÇAMLICA CADDESİ İHLAMUR VİLLALARI NO 28 / 6 ^^ŞRD 3K VİLLA ^^ Beylerbeyi –Üsküdar İSTANBUL / TURKEY P : +90 216 4220414 PBX F: +90 216 4220415
EDOPEC ENERJİ PETROL MÜHENDİSLİK SANAYİİ VE TİCARET LİMİTED ŞİRKETİ
www.edopec.com. [email protected]
Corrosion Management and Cathodic Protection
Edopec Corrosion divisions
is organized with a vision of providing engineering services and manufacturingfor Authorities and Clients located in Turkey , Iran , irak Syria and Middle-east.Libya ,Our focus is on complete Cathodic Protection services including all of theConsultation, Survey, Design, production and installation related work for On-shore & Off-shore facilities, Off-shore & Marine inspection and IndustrialAutomation for:
•Oil and Gas Industries (offshore & onshore)•Petrochemical industry•Energy•Cement industry
Edopec Co. carries out its business under five separate functionaldivisions as follows;
• Engineering Design and R&D• Manufacturing and Fabrication• Installation, Commissioning and Maintenance• Strategic Planning and Project Control• Financial and Commercial
Edopec. is a Company having a powerful blend of managementexperience, young and dynamics and technical expertise. Each Purchase orderor Work order is considered as a separated project and required team isorganized to undertake assigned Project manager to conduct the relevantsteps of Procurements, Quality Control, fabrication/erection/commissioningalong logistics and documents.
We continuously strive to perform all of our projects with the best quality tosatisfy clients' needs, using the qualified engineers and specialists. We realizedthat our success is largely dependent upon customer satisfactions witch isdirectly involved within each member products and managed projects.
Project Manger
Procurementbody
QC and Test body
Logistic coordinator
Technical Support
Erection GroupDocumentation
GroupElectrical Group
•PROJECT ACTİVİTİES
ACTIVITY DETAILS
ENGINEERING & DESIGN
Direct Assessments Services;Soil Resistivity Survey, CAT (Current Attenuation Test) Survey, DCVG (Direct Current Voltage/Gradient) Survey, CurrentRequirement/Drainage Survey, CIPS (Close Interval Potential) Survey, Stray Current Interference Survey, Polarization and On/Off PotentialSurvey, Coating Resistance Survey, Anode bed Resistance Survey, Buried Structures Natural Potential Survey, Overhead line Effect onBuried Structures Survey, (SRB) Sulphur Reduced Bacteria Survey, pH Survey, Carbonate And Sulphate Ions Survey, Grounding SystemResistance Survey, Internal Cathodic Protection and microbial corrosion monitoring and inspections.Engineering Design;Basic & Detailed Design of Cathodic Protection systems for Pipelines, Tank Forms, Petro-Chemical Plates, Power Plants, vessels, harbors,Jetties, offshore and marine structures by both means of SACP and ICCP system (where applicable) Design of SCADA based ICCP systems, Design of Stray Current and AC mitigation Systems.Materials/Equipment Design;Design and development of various types of CP Trans/rectifier Units, Design and development of Special Power Supply units, Design anddevelopment of RRU systems ( Remote Rectifier Units), Design and development of RMU systems ( Remote Monitoring Units), Design anddevelopment CP Remote Monitoring and Control systems. Design and development of GPS synchronized On/Off control of T/R units,Design and Development of Current Control boxes, Sacrificial anode design.
PROJECT MANAGEMENT Project management of SCADA based ICCP systems, Project management of ICCP and SACP systems, Project management of LocalCathodic Protection of Oil and Gas and Energy Facilities.
COMMISSIONING & START UP
Deepwell and shallow groundbed installations, ICCP systems for Pipelines and Storage Tanks, ICCP systems for Congested area andTank Farms, SACP installation for interior surfaces of storage tanks, SCADA based Cathodic Protection systems, CP Remote monitoring andControl systems, Galvanic CP and ICCP systems for Pipelines, Storage Tanks and Tank Farms, CP systems for Marine Structures andOffshore Pipelines, Galvanic CP and ICCP systems for Ships, Vessel, Jetties and Piers, Internal Galvanic CP and ICCP systems for WaterTanks and Boilers, Galvanic CP and ICCP systems for Reinforcing steel in Concrete Structures, SCADA communication systems (Wireless,Satellite, GSM, Fiber Optics) , Installation and replace of permanent reference electrodes under the tank bottom plate for further potentialmonitoring proposes via. horizontal drilling technology.
EQUIPMENT MANUFACTURE Fabrication and production of TR units ICCP anodes, Sacrificial anodes, current control and junction boxes, Coupons and referenceelectrodes.
•PRODUCTION and SUPPLY
Item Product1 Transformer Rectifier Units
2 Test, Junction, Bond Boxes
3 Current Control and Compensation Boxes
4 Reference electrodes and coupons
5 Cables and connections
6 Remote Monitoring System& Software
7 MMO coated Ti anodes
8 Silicon Iron Chromium Anodes
9 Magnesium anodes
10 Zn Anodes
11 Al Anodes
12 Backfill Materials
13 Miscellaneous
14 Cathodic Protection Software
•PRODUCTION and SUPPLY
•MAJOR CP SERVICES OFEDOPEC
•SITE SURVEYS & INSPECTIONSSERVICES•ENGINEERING DESIGN, PLANNINGAND R&D SERVICES•INSTALLATION AND COMISSIONINGSERVICES•BACK-UP SERVICES•TRAINING
SITE SURVEYS & INSPECTIONS SERVICESSite surveys are undertaken to evaluate the corrosion behaviour of different environments, Cathodic Protection monitoring, underwater inspection of structures, anodes, and coatings , Earthing and lightning activities by means of soil, water, location, stray current and so on testing. EDOPEC , undertakes the following surveys and inspections
•Soil Resistivity Survey•CAT (Current Attenuation Test) Survey•DCVG (Direct Current Voltage/Gradient) Survey•Current Requirement/Drainage Survey•CIPS (Close Interval Potential) Survey•Stray Current Interference Survey•Polarization and On/Off Potential Survey•Coating Resistance Survey•Anode bed Resistance Survey•Buried Structures Natural Potential Survey•Overhead line Effect on Buried Structures Survey•(SRB) Sulphur Reduced Bacteria Survey•pH Survey•Carbonate And Sulphate Ions Survey •Grounding System Resistance Survey•Contact Voltage (Touch and Step Voltages) Survey•Lightning Protection Installation Survey•Lightning Protection Level Survey •Internal Cathodic Protection and microbial corrosion monitoring and inspections.•Potential Profile, Current Distribution Survey of Power Plants, Take-off yards and substations
•Sub-sea Platform inspection for maximum deep of 40 meters including repair, wet welding, cutting, anode• inspection ( Cleaning, montage, re-montage, photography)and NDT tests (MPI, FMD, Thickness testes)
•BACK-UP SERVICES
EDOPEC . maintains close contact with the market so that it cantailor its product offering to the needs of the clients. Theconsiderable experience has ensured that the Company canprovide complete back-up services from initial design to finalcommissioning and maintenance. The aim is to give customers anefficient, professional service of the highest quality. Comprehensiverange of maintenance and support services provides a further levelof back up, as appropriate.
ENGINEERING DESIGN, PLANNING AND R&D SERVICES
The engineering and design phase is one of the key processes during the project execution stage. EDOPEC.Currently has a core staff of several engineers. All of these have been selected because of their unique alternativeexperience.We are more than able to provide our clients with the project teams to meet the challenges presented bymature fields.Advantages have been successfully involved in almost every advanced engineering project carried out in EDOPEC..Clients have recognised, through the provision of project services, EDOPEC’s ability to efficiently provide theirrequirements.
•Basic & Detailed Design of Cathodic Protection systems for Pipelines, Tank Forms, Petro-Chemical Plates, Power Plants,vessels, harbours, Jetties, offshore and marine structures by both means of Galvanic and ICCP system (where applicable).•Design and development of various types of CP Trans/rectifier Units•Design and development of Special Power Supply units•Design and development of RRU systems ( Remote Rectifier Units)•Design and development of RMU systems ( Remote Monitoring Units)•Design and development CP Remote Monitoring and Control Systems•Design and development of GPS synchronized On/Off control of T/R units•Project Design of SCADA based ICCP systems•Project Management of ICCP Galvanic CP systems•Project Design of Local Cathodic Protection of Oil and Gas and Energy Facilities•Design and Planning of CP installation of special ICCP anodes•Design and Planning of Subsea and Offshore Structure CP systems•Design and Planning of Ships and Vessels ICCP systems•Design and Planning SCADA communication systems•Design and Planning of ICCP Systems for Internal Cathodic Protection•R & D of CP systems of Reinforcing steel in Concrete Structures•R & D on AC interference analysis and mitigation system design•R & D on Projects Safety and Economics
•INSTALLATION AND COMISSIONING SERVICES
Edopec Co. have ability to provide installation and commissioning services for the following projects and systems relevant toOil & Gas and Energy Industries.
• Deepwell and shallow groundbed installations• ICCP systems for Pipelines and Storage Tanks• ICCP systems for Congested area and Tank Farms• Galvanic CP installation for interior surfaces of storage tanks• SCADA based Cathodic Protection systems• CP Remote monitoring and Control systems• Galvanic CP and ICCP systems for Pipelines, Storage Tanks and Tank Farms• CP systems for Marine Structures and Offshore Pipelines• Galvanic CP and ICCP systems for Ships, Vessel, Jetties and Piers• Internal Galvanic CP and ICCP systems for Water Tanks and Boilers• Galvanic CP and ICCP systems for Reinforcing steel in Concrete Structures• Ribbon anode installation for new constructed storage tanks• ICCP system for existing tanks using horizontal drilling technology.• Installation and replace of permanent reference electrodes under the tank bottom plate
for further potential monitoring proposes via. horizontal drilling technology.
Fundamentals of Corrosion Corrosion Cell:
Conditions required for corrosion Corrosion Rate Corrosion Types Commonly Affected Structures
Corrosion Control Materials Selection Inhibitors/Altering the environment Coatings Cathodic Protection
Measuring potentials Criteria
Fundamentals of Corrosion Corrosion Cell:
Conditions required for corrosion Corrosion Rate Corrosion Types Commonly Affected Structures
Corrosion Control Materials Selection Inhibitors/Altering the environment Coatings Cathodic Protection
Measuring potentials Criteria
Introduction to Corrosion
Corrosion can be defined as the deterioration of metal due to its interaction with the environment. Corrosion is a natural phenomenon, which should not surprise one, but rather should be expected to occur. Metals are high energy materials, which exist because heat energy was added to natural iron ores during the smelting process. Nature, by environmental contact, constantly attacks these high energy materials and breaks them down to the natural elements from which they were derived.
Conditions Required for Corrosion
Corrosion is an electrochemical process occurring at the interface between metal and environment. Three conditions must be present for this to occur.
1. Two areas on a structure or two structures must differ in electrical potential.
2. Those areas, called anodes and cathodes, must be electrically interconnected.
3. Those areas must be exposed to a common electrolyte (soil or water).
Two areas or two structures that differ in electrical potential (different amounts of stored energy)
The two areas, called the “Anode” and “Cathode”, must be electrically connected (conductive path)
Those areas must be exposed to a common electrolyte
CURRENTFLOW
CURRENT FLOWIONIZED ELECTROLYTE
WIRE
ANODE(IRON)
CATHODE(COPPER)
CURRENT FLOW(- TO + IN ELECTROLYTE)
Those areas must be exposed to a common electrolyte
CURRENTFLOW
CURRENT FLOWIONIZED ELECTROLYTE
WIRE
ANODE(IRON)
CATHODE(COPPER)
CURRENT FLOW(- TO + IN ELECTROLYTE)
Corrosion Cell – Dissimilar Metalsi.e. steel pipe connected to copper ground rod
CURRENTFLOW
CURRENT FLOWIONIZED ELECTROLYTE
WIRE
ANODE(IRON)
CATHODE(COPPER)
CURRENT FLOW(- TO + IN ELECTROLYTE)
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Corrosion Rate
As a result of this process, electric current flows through the interconnection between cathode and anode. The cathodic area is protected from corrosion damage at the expense of the metal, which is consumed at the anode. The amount of metal lost is directly proportional to the current flow. Mild steel is lost at approximately 20 pounds for each ampere flowing for a year.
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Factors Affecting Corrosion Rate
Potential Difference Between Anode and Cathode (Galvanic Series)
Circuit resistance – Resistivity of the Electrolyte Chemical Activity Stray Currents
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Potential Difference
Interconnecting two dissimilar metals in an electrolyte will create a corrosion cell. The strength of this cell increases as the distance within the galvanic series increases.
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Galvanic Series
METAL VOLTS (CSE) Commercially Pure Magnesium -1.75 Magnesium Alloy -1.60 Zinc -1.10 Aluminum Alloy -1.05 Commercially Pure Aluminum -0.80 Mild Steel (clean & shiny) -0.50 to -0.80 Mild Steel (rusted) -0.20 to -0.50 Cast Iron (not graphitized) -0.50 Lead -0.50 Mild Steel in Concrete -0.20 Copper, Brass, Bronze -0.20 High Silicon Cast Iron -0.20 Carbon, Graphite, Coke +0.30
Example: connecting magnesium to copper will produce a corrosion cell with a potential of about 1.5 volts.
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Circuit ResistanceCircuit resistance includes the following: Resistance of the anode Resistance of the cathode Resistance of the electrolyte Resistance of the metallic path
Increasing the resistance will reduce the corrosion rate.
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Resistance of Common Electrolytes
Soils – High resistivity water reduces the corrosion rate, while low resistivity water increases the corrosion rate.
CLASSIFICATION
ELECTROLYTERESISTIVITY
(ohm-cm)
ANTICIPATEDCORROSIVITY
Low Resistance 0 to 2,000 Severe
Medium 2,000 to 10,000 Moderate
High 10,000 to 30,000 Mild
Very High Above 30,000 Increasingly Less
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Resistance of Common Electrolytes
Water – Approximate resistivity valuesWater resistivity Ohms-cmopen sea 20-25 seawater (coastal) 30-40river water 500-10,000tap water 1,000-10,000 rain water 20,000distilled water 500,000pure water 20,000,000
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Chemical Activity
Passive (less corrosive) Environment High pH (neutral or basic) Low Moisture Content Lack of Salts High Resistivity Low Temperature Homogenous Environment
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Chemical Activity
Active (more corrosive) Environment Low pH (acidic) High Moisture Content Salts Low Resistivity Moderate to High Temperature Heterogeneous Environment
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Corrosion Type
Uniform or near uniform - Corrosion attacks all areas of the metal at the same or similar rate.
Localized - Some areas of the metal corrode at different rates due to heterogeneities in the metal or environment. This type of attack can approach pitting.
Pitting - Very highly localized attack resulting in small pits that may penetrate to perforation.
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Commonly Affected Structures
Buried Piping Steel Piles
Storage Tanks - Above Ground / Underground Reinforcing Steel in Concrete Ships/Boats
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Methods to Control Corrosion
Use of Corrosion resistant materials (plastic, stainless alloys, fiberglass).
Use of the same or similar metals per the galvanic series.
Altering the environment (utilizing homogeneous high resistivity backfill or inhibitors).
Utilize coatings and linings that electrically insulate the structure from the electrolyte (paints, plastic films, etc).
Use of Cathodic Protection.
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Fundamentals of Cathodic Protection
Cathodic Protection (CP) Defined - Minimize corrosion by utilizing an external source of electrical current which forces the entire structure to become a cathode.
41
1824: Earliest practical use of cathodic protection
Sir Humphrey Davy’s work on protecting the copper sheathing on wooden hulls in the British Navy by sacrificial zinc or iron anodes is generally considered to be the earliest example of practical cathodic protection.
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Galvanic CP
When metals such as magnesium or zinc are placed in the environment in contact with a more noble metal such as steel, a current flows from the more active anode to the noble cathode (corrosion cell).
43
Anodes Used for Galvanic CP
Magnesium – Magnesium is often used in soil to protect small electrically isolated structures, such as underground storage tanks, and well coated pipelines.
Zinc – Zinc is often used in marine environments. They are commonly found on boats.
Aluminum – Aluminum can be used for a variety of marine applications.
Anodes Used for Galvanic CP
44
Keys to obtaining enough cathodic protection
Determine amount of current requiredTheoretical calculations based on coating quality and environmentOr, perform current requirement testing Calculate output expected from anode and determine number of anodes required.
45
Galvanic CP
Pros of Galvanic CP Inexpensive Little Maintenance cost No external Power source A variety of install methods can be used. For
example, many UST’s are shipped with anodes attached.
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Galvanic CP
Cons of Galvanic CP Typically work best with electrically isolated structures. No external power source, limited driving potential
(driving potential based on the galvanic series) Limited output makes it ineffective when trying to
protect large uncoated surfaces. Require a low resistivity electrolyte to function well.
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Impressed Current CP
Utilize an external power source to develop a high potential difference between the surface to be protected and an anode.
Impressed Current CP
Anode Groundbed
Rectifier
Negative Cable
Positive Cable
AC Power Supply
Pipeline
IMPRESSED CURRENT SYSTEM
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Impressed Current CP
Pros of Impressed Current CP Unlimited driving potential. Capable of protecting large steel structures
when designed properly. Requires less anodes then a galvanic system. Output can be controlled using a permanent
reference electrode, desirable when the electrolyte resistivity is known to change.
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Impressed Current CP
Cons of Impressed Current CP Initial costs can be more expensive. Requires an external DC power source along
with an AC supply. System requires routine maintenance and
monitoring. Anode wires can be susceptible to damage.
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Impressed Current CP Rectifier
A rectifier converts available AC power to low voltage DC power. Most cathodic protection rectifiers are provided with a means to vary the DC output voltage in small increments, or in some cases offer complete control from zero to 100% of rated DC output.
Impressed Current CP Rectifier
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CP System Testing
A CP system can be evaluated by obtaining a reference cell potential. This potential determines the amount of cathodic polarization the structure is receiving.
Adequate protection is indicated by obtaining a value more negative then the established criteria.
This criteria is specific to the reference cell used to obtain potentials.